Itunes or hardware problem Not sure which

I don't know if this is a hardware or software issue.
I turned my Spring 2011 Mac Mini into our home music system, using an external hard drive to hold the music.
For the living room, run speakers off the external headphone jack.
Both bedrooms each have an Airport Express to run speakers.
Also have an Airport Extreme to run WI-FI in the house. Which is off of a Time Warner modem.
Also have one cell phone running off of Sprint.
And 2 iPads, one runs off the TWC WI-FI,
The other cell phone runs off of Verizon and when needed Verizon Wi-FI for the other iPad. Usually the TWC to save costs.
I'm showing 2 strong WI-FIs nearby. One could be ATT U-Verse, the other is probably a Google Fiber. (I'm in one of the 1st neighborhoods).
Also a newer Mini that seems to hog resources. Too many open tabs on Safari, Firefox & Google. Maybe I just solved my own problem.

PROBLEM:
About once a day one or the other the sets of bedroom speakers goes into stuttering mode, while everything else is OK. I turn off iTunes, restart and everything works. Can the stuttering be fixed easy?

That's likely either:
- the Mini isn't serving the data fast enough (ensure you plenty of RAM and disk space available and that you don't have other processes constantly accessing the disk or maxing out the CPU.
OR
- more likely you're getting interrupted wifi. Try using a tool like iStumbler to 'see' the other wifi networks in the area and the channels being used and switch your channel to be as far away from surrounding networks as possible.

External hard disk acquisition addict - but admitting the problem is the first step to a robust backupPlease use the reputation system if you think you've been helped - top right of this post